[Techtoolslist] 9100 ROM Signature Algorithm

[Martin White]

On 26 Aug 2010, at 16:22, John Robertson wrote:


> martin at guddler.co.uk wrote:

>> Hi John.

>> 

>> Unfortunately that's all for the 9010. I'm talking about the 9100 and the sigs are different.

>> 

>> Martin

>>  

> 

> Ah, right - didn't the 9100 just use regular checksums for its 'Signatures'?  In which case there is RomSum.exe that will generate checksums for individual files or entire directories, printing the results to screen or piped to a file.

> 

> John :-#)#



It doesn't seem so, no.

I just went and read in 'galtest.bin' the (or a) galaxian test rom.

Here's what I get (the first ones are various CRCs my programmer can produce):

The layout will probably be messed up so sorry about that.

		Sum		Neg.		Suppl.
Byte		00050839	FFFAF7C6	FFFAF7C7
Word		028BB800	FD7447FF	FD744800
Byte(CY)	00050839	FFFAF7C6	FFFAF7C7
Word(CY)	028BB800	FD7447FF	FD744800
CRC-CCITT	D8F7		2708		2709
CRC-XModem	548D		AB72		AB73
CRC-32		0614CD7F

Fluke 9100	052C
Fluke 9010	4AFE
RomSum	0839

As we can see at the bottom here, the three we see in the arcade world are all different. I grabbed RomSum from a link on the flippers site so I assume it's the one you're talking about?

Apologies to those on the list who are not here from the arcade world!

I'm going to go investigating further.

Martin.


>> On 26 Aug 2010, at 00:49, John Robertson <jrr at flippers.com> wrote:

>> 

>>  

>>> Martin White wrote:

>>>    

>>>> Hi all,

>>>> 

>>>> I'm pretty sure the answer to this is no, but did anyone ever work this one out? Ie how to calculate the sigs from ROMs?

>>>> 

>>>> It's never really been a show stopper for me since I check against the CRC32 sigs first thanks to a script that Andy Welburn posted up some years back (with assistance from Chris Hardy I believe?) and then when I know a ROM matches and the fluke can read it in-circuit ok I then use the 9100 to get the 9100 sig.

>>>> 

>>>> It's a bit of a drag though as the CRC32 calculation is kinda slow (even on the FT) so it would be nice to have the 9100 sig up front.

>>>> 

>>>> Martin.

>>>>       

>>> Hi Martin,

>>> 

>>> Yes, that was worked out and made into a nice utility program that you can download from Quarterarcade (a big THANKS to James Bright for this work!) @

>>> 

>>> http://tech.quarterarcade.com/tech/Fluke/9010A/

>>> 

>>> The FIDE software allows you to input your files that you want ROM Signatures and it does the rest.

>>> 

>>> John :-#)#